Forest Investment Account (FIA) - Forest Science Program
FIA Project M086020

    Predicting development and productivity of southern interior mixed species stands following mountain pine beetle attack
Project lead: Simard, Suzanne (University of British Columbia)
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Here, we propose to parameterize the SORTIE-BC stand dynamics model for Montane spruce zone stands in the southern interior of BC. Similar work is currently being funded by the Forest Science Program for southern interior ICH subzones (FSP #Y062067). In order for the SORTIE-BC model to make accurate stand growth predictions for the MS zone, including MPB affected areas, it is necessary to sample a range of stands characteristic of the zone. Unfortunately, due to the MPB infestation and recent salvage operations many of the stands necessary for parameterization, particularly those containing mature lodgepole pine, are becoming scarce in the southern interior. Without the information collected from these rapidly disappearing stands it will be impossible to parameterize the SORTIE-BC model for the MS zone. To parameterize the SORTIE-BC model we will quantify the growth response of juvenile trees (<10 cm dia.) growing under a range of light environments, characterize the probability of juvenile tree mortality, and investigate the effects of competition on the growth and survival of adult trees (>10cm dia). The primary tree species we will collect data for include; lodgepole pine, subalpine fir and spruce. Our empirical data will be linked to SORTIE-BC. SORTIE-BC is a resource-mediated, spatially explicit, mixed-species forest model that makes population dynamic forecasts for juvenile and adult trees. It has a flexible user-interface that allows incorporation of a wide range of silvicultural strategies (e.g., clearcutting, understory protection, understory planting, diameter limit harvesting, shelterwood, single or group selection and variable retention). With the model, we can examine how stands will develop following MPB attack. We will be able to evaluate and estimate timber growth implications on residual trees and regenerated stands in the understory and in clearcut openings. We will also be able to predict residual stand development with and without treatment under various levels of attack. This research will clearly aid the development of science-based policies, regulations and guidelines for the management of mountain pine beetle affected stands. Approach: This study will be conducted in the MS zone of the Southern Interior Forest Region. Initially we will focus on collecting information for lodgepole pine. To determine the growth response of lodgepole pine to a variety of light conditions, we will collect radial growth information from approximately 60 trees growing under different light conditions. We will also sample live and dead saplings across a heterogeneous light environment to characterize the probability of juvenile mortality as a function of recent growth. To develop this relationship, stem cross sections are collected from approximately 40 living and 40 recently dead trees for each species. By sampling a variety of stand ages, from age class 2 to 9, we will be able to develop distance-dependent models to determine the effects of competition on growth and survival of adult trees (Canham et al., 2004). In each stand, a central transect 50-350 m long is established, and we number and record species, DBH and location of each tree with a DBH ? 10cm within 20 m of the transect center-line. In total 100-150 target trees are sampled for each species. Once we have completed sampling for lodgepole pine, we will shift our focus to other MS zone tree species, primarily subalpine fir and spruce. It is important to note that we have already collected information on the growth response of juvenile subalpine fir to a variety of light conditions. This data has been collected through another FSP funded project (Y062066), (Y061028) - Improving predictions of juvenile tree growth in complex mixtures for sustainable forest management. Measurements: -Each sample tree is assessed for height and DBH to characterize the growth response of our test species to variations in light. The sample trees are cut down and a stem cross section collected 10 cm above the ground. The 10 most recent annual growth rings are measured using a Vellmex Micrometer. Hemispherical canopy photos are taken 1.5 m above the stump of each cut sample tree to quantify the level of available light (This information has already been collected for subalpine fir through another FSP funded project, as described above). -To examine the probability of mortality as a function of recent growth, a stem cross section is removed from the chosen sample trees 10 cm above the ground. The 10 most recent annual growth rings are measured using a Vellmex Micrometer. A subsample of randomly placed quadrants is used to estimate the total number of live and dead individuals on each site. This information, along with the growth data collected from the disks, is required for maximum likelihood analysis. -To quantify effects of competition on the growth and survival of adult trees, stands of various ages are stem mapped. This is done using an Impulse LaserTM with the Mapstar Compass ModuleTM. All trees meeting the necessary requirements are mapped, tagged, and assessed for species and DBH. Target trees are cored and a Vellmex Micrometer used to determine the average radial growth (mm/yr) over the last 5yrs. Analyses: 1)The analysis of growth response data to variations in light will require the use of nonlinear regression to develop growth functions as described in Wright et al. 1998. 2)Maximum likelihood analysis, as described in Kobe and Coates 1997, will be used to determine the probability of mortality as a function of tree growth. 3)The analysis of the competition data will follow the techniques outlined by Canham et al. (2004). 4)Dave Coates will oversee the parameterization of the SORTIE-BC stand model. He has already conducted similar research for many tree species in northern BC.
Related projects:  FSP_Y102095


Final Technical Report (1.1Mb)

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Updated August 16, 2010 

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